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last day (of a month)
家賃は末日までに支払う。
Rent must be paid by the last day of the month.
契約は今月の末日が満了日です。
The contract expires on the last day of this month.
経理部は毎月の末日に必ず帳簿を締め切ります。
The accounting department always closes the books on the last day of every month.